Project Summary: Most of the drugs that are used to treat the diseases plaguing mankind are made, or synthesized, by humans, rather than being isolated from natural sources. Therefore, it is very important to keep developing new reactions for synthesizing ?drug-like? molecules, likely to have beneficial activity. This proposal describes an investigation of a series of reactions, all related to one particular reaction, the ?interrupted? Feist-Bnary (IFB) reaction. These reactions generate molecular structures present in a number of molecules that have the potential to treat such conditions as fungal and viral infections, along with some forms of cancer. Furthermore, these reactions control the chirality of these molecular structures. Chirality is a property associated with the three-dimensional shape of a molecule and is fundamental in determining how a molecule interacts with a biological system. It is also particularly difficult to control the chirality of a product, but the IFB and related reactions very effectively do this for the creation of the drug-like molecular structures. The proposal describes plans for discovering new reactions, for testing how wide a variety of products the reactions can produce, and for using the reactions in the synthesis of several families of biologically active, potentially clinically useful molecules.